Prostate cancer is the most common type of cancer in men in the USA. Benign prostatic hyperplasia (BPH) is the abnormal growth of benign prostate cells in which the prostate grows and pushes against the urethra and bladder, blocking the normal flow of urine. More than half of the men in the USA, aged 60-70 and as many as 90% percent aged 70-90 have symptoms of BPH. Although BPH is seldom a threat to life, it may require treatment to relieve symptoms.
References 1 and 2 disclose that human endogenous retroviruses (HERVs) of the HML-2 subgroup of the HERV-K family show up-regulated expression in prostate tumors. This finding is disclosed as being useful in prostate cancer screening, diagnosis and therapy. In particular, higher levels of an HML-2 expression product relative to normal tissue are said to indicate that the patient from whom the sample was taken has cancer.
Reference 3 discloses that a specific member of the HML-2 family located in chromosome 22 at 20.428 megabases (22q11.2) is preferentially and significantly up-regulated in prostate tumors. This endogenous retrovirus (termed ‘PCAV’) has several features not found in other members of the HERV-K family: (1) it has a specific nucleotide sequence which distinguishes it from other HERVs within the genome; (2) it has tandem 5′LTRs; (3) it has a fragmented 3′LTR; (4) its env gene is interrupted by an alu insertion; and (5) its gag contains a unique insertion. Reference 3 teaches that these features can be exploited in prostate cancer screening, diagnosis and therapy.
References 1 to 3 disclose in general terms vectors for expression of HML-2 and PCAV polypeptides. It is an object of the invention to provide additional and improved vectors for in vitro or in vivo expression of HML-2 and PCAV polypeptides.